Serious Fun With Flexagons

A flexagon is a motion structure that has the appearance of a ring of hinged polygons. It can be flexed to display different pairs of faces, usually in cyclic order. Flexagons can be appreciated as toys or puzzles, as a recreational mathematics topic, and as the subject of serious mathematical study. Workable paper models of flexagons are easy to make and entertaining to manipulate. The mathematics of flexagons is complex, and how a flexagon works is not immediately obvious on examination of a paper model. Recent geometric analysis, included in the book, has improved theoretical understanding of flexagons, especially relationships between different types. This profusely illustrated book is arranged in a logical order appropriate for a textbook on the geometry of flexagons. It is written so that it can be enjoyed at both the recreational mathematics level, and at the serious mathematics level. The only prerequisite is some knowledge of elementary geometry, including properties of polygons. A feature of the book is a compendium of over 100 nets for making paper models of some of the more interesting flexagons, chosen to complement the text. These are accurately drawn and reproduced at half full size. Many of the nets have not previously been published. Instructions for assembling and manipulating the flexagons are included.

The history of mathematics is replete with examples of major breakthroughs resulting from solutions to recreational problems. The modern theory of probability arose out of problems of concern to gamblers, for example, and modern combinatorics grew out of various games and puzzles. Despite this track record and a wealth of popular-level books, there remain few conduits for research in recreational mathematics. The Mathematics of Various Entertaining Subjects now returns with an all-new third volume, presenting new research in diverse areas of recreational mathematics. This volume focuses on four areas: puzzles and brainteasers, games, algebra and number theory, and geometry and topology. Readers will create Spiral Galaxies, Japanese symmetric grid puzzles consisting of squares and circles whose solutions are letters and numbers; delve into a paradox in the game of Bingo; examine the card tricks of mathematician-philosopher Charles Sanders Peirce; learn about the mathematics behind Legos; and much more. Elucidating the many connections between mathematics and games, The Mathematics of Various Entertaining Subjects is sure to challenge and inspire mathematicians and math enthusiasts.

Martin Gardner enormously expanded the field of recreational mathematics with the Mathematical Games columns he wrote for Scientific American for over 25 years and the more than 70 books he published. He also had a long relationship with the Mathematical Association of America, publishing articles in MAA journals right up to his death in 2010. This book collects the articles Gardner wrote for the MAA in the twenty-first century, together with other articles the MAA published from 1999 to 2012 that spring from and comment on his work.

This book complements available one-make books on domestic synchronous clocks. It is also a history of science book that sets British domestic synchronous clocks, their manufacturers and technology in their social context. Part I covers the historical background, British domestic synchronous clock manufacturers and brands, how synchronous clocks work, domestic synchronous clock cases, practical advice on the servicing of domestic synchronous clocks and analysis of the marketing and reliability of British domestic synchronous clocks. This analysis provides an explanation of the rise and eventual fall of their technology. Part II contains galleries of a selection of British domestic synchronous clocks and of the movements with which they are fitted. There is a front and back view of each clock, together with a brief description. Views of each movement include views with the movement partly dismantled, together with a brief technical description of the movement. This profusely illustrated book is primarily for fellow enthusiasts and is based on an extensive archive of information on domestic synchronous clocks, their movements and their manufacturers. Current electrical regulations mean that professional clockmakers are reluctant to repair synchronous clocks. In fact, provided that they have not been mistreated, synchronous clocks are usually reliable, and quite easy to maintain.

ALL YOU NEED IS PAPER! All the puzzles inside are made out of paper — from simple teasers to extreme brain workouts! ORIGINAL DESIGNS Co-developed by a mathematician, an origami artist and a mechanical puzzle maker, this inventive book provides a unique and invaluable collection of a large, comprehensive and diverse variety of paper puzzles. And they only require a sheet of paper and perhaps a pair of scissors! EASY TO CHALLENGING There are 99 unique puzzles including paper strip puzzles, Möbius strips and flexagons, two-dimensional sheet folding, 'fold-and-cut' puzzles, 3D dissections and constructions, sequence folding puzzles, origami puzzles and even paper toys and magic. PROVIDES HOURS OF FUN Anyone of any age can find hours of enjoyment and challenge! LEARNING GEOMETRY, MATHEMATICS AND PROBLEM-SOLVING CHALLENGES CAN BE FUN! For students and teachers; parents and children; amateur and skilled mathematicians, and puzzle lovers. LEARN CONCEPTS AS YOU GO! Many of the puzzles are new and original, they complement the classic puzzles that are included and all of them come with a solution as well as a mathematical and geometrical explanation that can be easily understood by all. The layout of the book, with its extensive puzzles, solutions and detailed descriptions, make it a sure candidate as the paper puzzle 'bible' for enthusiasts and puzzle lovers everywhere. Contents: Just FoldingOrigami Puzzles3D Folding PuzzlesSequence FoldingStrips of PaperFlexagonsFold and CutJust CuttingOverlapping Paper PuzzlesMore Fun with Paper Readership: Puzzle and riddle lovers, and origami enthusiasts. Keywords: Puzzle;Paper;Recreational Mathematics;Geometry;Origami;Fold;CutReview: Key Features: Many new and original puzzlesA huge collection of paper puzzles and activities for all ages and levelsBoth educational and fun; highly challenging puzzlesPresents many geometrical and mathematical principals in an easy to understand mannerPossibly the only book in the market that contains such a large and diverse collection of paper puzzles

Are you ready to flip out? Hexaflexagons are six-sided, flat paper models that can be made to reveal hidden images through a series of flexes and folds. Flexagons were first introduced in a column written by Martin Gardner for Scientific American. From there, people started folding and figuring out creative ways to craft these interesting origami-like objects. Included in this delightful book are instructions and material to create hexaflexagons, tri-tetra flexagons, cubes, flexacubes, and more! Flexing kaleidocycles are shapes formed by taking several tetrahedra (four-sided 3D shapes) and joining their edges to form a ring, which can then be rotated so that it turns inside out to display a multitude different colors, shapes, and designs! This book contains: • A brief introduction on the history of hexaflexagons • Instructions on how to make 13 different fun flexagon models • 40 pages of easy tear-out pages with pieces to assemble your hexaflexagons People are still discovering new ways to innovate with these enjoyable creations—so with some study and practice, you may be able to come up with a unique design and enter the pages of flexagon history! All you need to do is to cut out and assemble the various models in this book to create the most intriguing and entertaining designs available. Start folding your flexagons now!

Flexagons are hinged polygons that have the intriguing property of displaying different pairs of faces when they are flexed. Workable paper models of flexagons are easy to make and entertaining to manipulate. Flexagons have a surprisingly complex mathematical structure and just how a flexagon works is not obvious on casual examination of a paper model. Flexagons may be appreciated at three different levels. Firstly as toys or puzzles, secondly as a recreational mathematics topic and finally as the subject of serious mathematical study. This book is written for anyone interested in puzzles or recreational maths. No previous knowledge of flexagons is assumed, and the only pre-requisite is some knowledge of elementary geometry. An attractive feature of the book is a collection of nets, with assembly instructions, for a wide range of paper models of flexagons. These are printed full size and laid out so they can be photocopied.